Machine for spray coating the interior of containers



R. w. SMITH 2,557,479

momma FOR SPRAY-COATING THE INTERIOR 0F counmsas June 19, 1951 4 Sheets-Sheet 1 Filed, July 23 1949 INVENTOR Pober/ W Smifh ATTORN June 19, 1951 R. w. SMITH 2,557,479

MACHINE FOR SPRAY-COATING THE INTERIOR 0F CONTAINERS Filed July 2:5, 1949 V 4 Sheets-Sheet 2 mvsnrron Faber) W Smi/h ATTORNEY Jun 19, 1951 R. w. SMITH 2,557,479

MACHINE FOR span-comma THE INTERIOR o'F CONTAINERS Filed July 25, 1949 '4 Sheets-Shag: s

g X 3 I8 43 l9 5/ /2 44 13 ,7 '3, 46 63 n I I r 54 66 49 47 E L'g.6'

1 CONVEYOR l/8 /7 9 :mrcl/ 23 1 //z SOLE/V010 l VALVE SPRAY GUN .21 7 l M v |5OLNOID 4 VAL E AIR I Z co/vvsvon SOLENOID VALVE 14/2 SPRAY 6 .31 8 13, 7 a4 29 uvmvrox {32 1 Robe/'7 W- Smifh ATTORNEY June 19, 1951 w, $M|TH I 2,557,479

MACHINE FORSPRAY-COATING THE INTERIOR 0F CONTAINERS Filed July 23, 1949 Q 14 Sheets-Sheet 4 m4 v M7 w /'6/ PAN TRAVEL joys/"EH7, I

SOLE/V010 VA V5 SWITCH {52 SPRAY GUN 174 W 'f'igjj IN VEN TOR. I

ATTORNE Patented June 19, 1951 MACHINE FOR SPRAY COATING THE INTERIOR 0F CONTAINERS Robert W. Smith, San Carlos, CaliL, assignor to Ferry Sheet Metal Works, Inc., a corporation of California Application July 23, 1949, Serial No. 106,400

9 Claims.

This invention relates to machines for applying a coating to the interior surface of a container such as a bread pan, a battery box or the like.

In various industries, it is desirable that the interior surface of a container be adequately covered with a coating composition. For example, in the manufacture of composition to the several compartments of the box to provide added resistance to the sulphuric acid utilized as the electrolyte in the storage battery. In the baking industry, it is usual to apply to the pans a coating of a suitable shortening, grease or the like.

The present invention will be particularly described as it has been successfully employed in the baking-industry; however, it is to be understood that it is not limited to this use and that it is capable of general application. The machine of the present invention is particularly characterized in that it enables a uniform coating of a desirel weight to be applied to the several surfaces defining an interior cavity in a container, usually a bottom and four sides extending generally vertically. Further, the present invention is characterized in that the device enables a coating composition to be applied successfully and uniformly to the bottom and side walls defining the cavity to be coated without applying the material to the upper edges and to the exterior surface of the container, such application being deemed in the industry inacceptable and unwanted for various reasons.

In general the broad object of the invention is to provide a novel spray coating machine for applying a spray composition to the container walls defining a cavity.

Another object of the present invention is to provide a spraying machine inwhich containers can be continuously spray-coated.

The invention includes other objects and fea tures of advantage, some of which, together with the foregoing, will appear hereinafter wherein the present preferred form of device of this invention is disclosed.

In the drawing accompanying and forming a part thereof,

Figure 1 is a section taken transversely through a machine embodying the present invention.

Figure 2 is a side elevation showing a portion of the control mechanism utilized.

Figure 3 is a section taken transversely along the run of the conveyor, illustrating the relationship between the spray gun, containers undergoing spraying and the control mechanism.

Figure 4 is a section taken transversely through a portion of the control mechanism illustrating the valve structures utilized.

. device.

Figure 5 is a schematic showing of some of the apparatus employed and the flow diagram for the air supply.

Figure 6 is sectional view like Figure 1 but showing a modified form of the invention.

Figures 7 and 8 are diagrams illustrating various control systems which can be employed.

Figure 9 is a plan view of another control Figure 10 is a side elevation of the control device shown in Figure 9, additional mechanism being included diagrammatically to illustrate the manner of using this device.

Figure 11 is a side elevation of another form of control device.

Briefly characterized, the present invention includes oneor more spray devices suitably positioned to discharge the material to be sprayed into the container; each spray device is fluidoperated and includes means effective upon application of fluid pressure to release fluid for atomizing the material to be sprayed. In accordance with the present invention, the fluid-operating means is operated by a fluid under relatively high pressure so that relatively rapid starting and stopping of atomization is assured. Further, in accordance with this invention, the operation is so regulated that the material sprayed is applied only to the interior of the cavity and'not to the exterior surfaces of the walls defining the cavity.

Referring to the drawing, and particularly to Figures 1 and 3, a continuous conveyor generally indicated by numeral II is included and comprises two spaced chains movable continuously along rails I3 from left to right in Figure 3 by suitable means which are conventional in the conveyor art and are therefore readily supplied by those skilled in the art. The conveyor il moves the containers to be coated, in this instance, bread pan units, generally indicated by numeral [6 and comprising several pans ll joined together to provide a unit by a strap member I! which extends along each of the ends of the several pans and along a side of the front and the rear pans. Rails [9 are positioned cooperatively adjacent to the sides of the pan unit ii to guide the unit during movement by conveyors II. The several pans in each unit are spaced apart. The units may follow one another when fed into the machine or they may be fed in at irregular intervals. In either case, the machine is capable of handling them.

a cross member 28 upon which are mounted movable brackets II, each having an arm 2| adjustably retained within a spray gun generally indicated at II. The spray gun employed is of a type well known in the art and includes a spray noszle generally indicated by numeral ll and adapted to spray a fiuid supplied under substantially constant pressure and at the requisite temperature through line 32 in atomized form under the pressure of air or other suitable fiuid through line 83. The gun includes mechanism adapted to be opened and closed, upon controlled application of high pressure fluid through line 84, to admit or shut off the fiow of low pressure atomiaing fiuid through line 33. In the form or the device illustrated, in Figure 1 a single gun is shown, while in Figure 6 two guns are shown in position; more can be utilized as desired, it onlybeing necessary to supply suitable fiuid and air to each of the guns under the control of one of the presently described control mechanhm. The gun shown in Figures 1 and 3 includes two spray nozzles 35, each making a spray application to a limited portion of one end wall, the side walls and a portion of the bottom, the areas sprayed by each nozzle overlapping slightly to ensure complete coating.

As is shown particularly in Figure l, a first control rod ll extends transversely of the machine and is Journalled in bearings 42 and 43. A finger It is adiustably secured to the rod 4i and extends upwardly to engage the under side of a bread pan or other container, as it appears in Figure 3. Similarly, a second control rod It is provided transversely of the machine and is journalled in bearings l1 and 48, a finger 49 extending upwardly to the same elevation as finger 44 as appeared in Figures 2 and 3, but slightly in advance of finger 44 for reasons which will presently appear. v

A lever Si is secured on one end of rod ll, the extending end of the lever 5i carrying a stud l2 slidably engaged in a slot 53 in arm 55 of bell crank head 54. The bell crank is hinged at 58 and its other arm 58 extends down to operate a valve mechanism generally indicated at Ii and carried in the control unit generally indicated by number [2. Rod 46 includes a lever 61 thereon normally biased in a counterclockwise direction (Figure 2) by a spring 84 and into engagement with valve mechanism 68 in the control unit 62. Each of the valve mechanism 6i and 66 are identical and a description of one will sufilce for a description of the other. As is shown in Figure 4, the control unit 62 includes a first cavity Ii in which is positioned a spring 12 carrying a valve member", the spring urging the valve member II into closing position with respect to a port II in a member I8, the latter being positioned at the bottom of a second cavity 11 in unit 82. Member 16 is retained in position by a cage structure II provided as an extension upon a threaded member Ill adapted to be screwed into 4 the unit 62 as a closure for the second cavity. A pin ll extends through a stuffing gland 82 in the threaded member I! and into engagement with valve member ll.

Referring to Figure 4, the valve body includes an inlet opening I! through which air or other high pressure is supplied from a pipe It, the latter being connected to a pressure regulator II which is in turn supplied with fluid from supply 02 by conduit 0; for convenience, air is usually employed and hereinafter will be employed in describing the mechanism and its operation. The inlet 82 in the control unit 62 is connected by a duct \to the first cavity Ii associated with the first valve member ii. Air passing through the port I4 and through the openings in the cage II is conducted through a duct It to the first cavity 1| associated with the second valve member it and, under the control of this valve member, through duct 81 to an outlet pipe It, and thence to line 34 and to the spray gun to control air for spraying. Air for the spraying operation is supplied by line I] from regulator 94 which is in turn supplied by line I from supply 92. In one successful machine, regulator 9| delivered air at 85 pounds per square inch gauge and regulator 94 at 8 pounds per square inch gauge. In this way, rapid release of air for spraying is secured as is the period of spraying.

In operation, line 33 is connected to a low pressure air supply and line It in the gun to a high pressure supply under the control of the valve mechanism 62, while line 32 is connected to a suitable supply of the material to be applied to the containers. With conveyor ii operating continuously and a supply of containers passing more or less regularly through the device, the front edge of a container depresse finger II and rocks this in a clock-wise direction in Figure 2; this results in air passage through the line 34 and a spray application to the pan. This continues as long as finger N is depressed and until finger It is rocked clockwise in Figure 2; when this occurs, valve 66 is closed and the supply of air to the spray nozzle is cut oil, even though finger N is still depressed. The two fingers H and 49 must be spaced apart a distance only sufilcient to permit a complete spray application to the selected area of the side walls and the bottom of each container during traverse of each container beneath the spray guns. This distance is related to the width of the bottom of each container with which the fingers are in contact and to the angle at which each spray gun discharges. In the device shown, the spray cut-ofi' occurs while half the container bottom is still to pass over control finger II. This ensures spray coating of the bottom and the side walls without coating of the rim or outer edges of the container. When the container superimposed over fingers N and I! has moved along to the point where finger ll is released, finger is still depressed and the spraying cannot occur. However, as soon as finger 4! is released, the mechanism is ready for another spraying application upon rocking of finger 44 in a clockwise direction in Figure 2.

It is possible to control the spray gun in various ways and in Figures 7-11 I have illustrated various apparatus arrangements which can be utilized to secure the required spray coat application and to maintain control of such application with each pan. Referring particularly to Figure 7, I have shown spray gun 29 as supplied with air through line Iii, under the control of a solenoid valve II2, this valve being in tum supplied with air through line I I3 under the control of solenoid valve II4 from a suitable source indicated at I I6. Solenoid valve I I2 is normally open while solenoid valve II4 is normally closed. Valve H4 is controlled by a switch II1 having an actuator arm II8; similarly, solenoid valve H2 is controlled by switch II9 having an actuator arm I2I. Each of the actuator arms H8 and I2I is positioned to engage the bottom of a pan on conveyor II, the switches being supplied with power from lines I22 and I23 to operate the respective solenoid valves.

In operation, with conveyor I I moving continuously, a pan first engages switch actuator II8 whereby switch H1 is closed and solenoid valve H4 is opened to admit air through line II3, through valve H2 and through line III to the spray gun 29. This continues and the spray gun applies a suitable coating to the pan so long as switch H8 is depressed and switch actuator I2I is not engaged; immediately upon the pan bottom engaging the switch actuator I2I, solenoid valve H2 is closed to interrupt the supply of air to gun 29, even though the pan is still in a position wherein it is in engagement with switch actuator II8. This insures that the desired area of the pan will be coated, that is, the bottom and the requisite portion of the side wall area.

A similar operation can be secured with the arrangement shown in Figure 8 wherein spray gun 29 is supplied with air from line I3I under the control of a solenoid valve I32 from a suitable source I33. The solenoid valve I32 is placed in series with a switch I34 and a switch I36, the switches being supplied with power from lines I31 and I38. Switch I34 includes an actuator I, while switch I36 includes an actuator I42; the actuators are positioned to engage successively the bottom of a pan as it is moved along by conveyor II. Switch I34 is normally open when the actuator I is in the raised position, while switch I36 is normally closed when the actuator I 42 is in its raised position. Thus, as conveyor I I moves a pan along, the pan will engage actuator MI and close switch I34 whereupon current will be supplied to open the solenoid valve, switch I36 being normally closed. The supply of air will be discontinued immediately upon actuation of actuator I42 and the opening of switch I36.

Referring particularly to Figures 9 and 10, a

switch I5I is provided to control the supply of power from lines I52 and I53 to solenoid valve I54, the latter controlling the supply of air from source I56 to line' I51 to spray gun 29. Switch I5I includes an actuator rod I58 which is nor- I mally biased to move upwardly.

The switch includes a bracket I6I mounted on the side thereof and having a rod I62 extended between the ends of the bracket. A-=first member I64 is mounted upon the rod I62, the member I 64 being bifurcated and having two arms I66 which extend horizontally from a vertical, panengaging portion I61. 'Mounted between the spaced arms I66 is another pan-engaging member I68, the latter being mounted on rod I62. A spring I69 is extended between member I64 and member I68, its force being applied in such direction that the horizontal portions of members I64 and I68 are normally in thesame plane. The end of the switch actuator I58 rides on the horizontal portion of member I68.

In operation, the switch actuator I58 and the pan-engaging members I64 and I68 are normally in the full line position shown in Figure and the switch is open. Upon a pan engageing the first pan-engaging member I64, the entire switch actuator is depressed, spring I69 being of suflicient strength to rock pan-engaging member I68 simultaneously with the counterclockwise rotation of pan-engaging member I64 about rod I62. As the pan movement continues, member I68 is engaged and rocked clockwise and, since the switch actuator I58 is in engagement with the pan-engaging member I68, the switch actuator is permitted to move'upwardly to open the switch and discontinue the supply of air to the spray gun 29.

Referring to Figure 11, I have shown another modified form of the device and which includes a valve casing I" having a slidable valve element I12 therein and which is moved by an arm I13 from a suitable solenoid (not shown). The valve casing includes a'closure I14 at one end thereof, a spring I16 being placed between this closure and the slidable valve I12. At the other end of the body, a closure I11 is provided and includes an air escape aperture or passage I18, controlled by a needle valve I19. Air to be supplied to the spray gun is admitted through conduit I8I and passage I82 in the valve. body to an outlet passage I83 which is connected to the spray gun; an exhaust passage I84 is provided and is connected to the spray gun by a passage I 86 in the valve body.

In operation, the solenoid for moving the arm I13 is energized momentarily, as by a switch placed in the path of a pan and which switch is closed to move the solenoid arm to the left in Figure 11. This brings passage I82 into alignment with the air supply passage I8I and the spray gun passage I83, whereby air is supplied to the spray gun. Upon de-energization of the solenoid, spring I16 becomes effective to force the valve to the right in Figure 11 against the slow escape provided by the controlled outlet through passage I18. The air escape through passage I 18 is regulated to permit of the application of air' to the spray gun for the desired period of time. Upon cessation of the spraying operation, the residual air trapped in the gun and in the line to the gun is released through passage I86 and exhaust port I84.

From the foregoing, I believe it will be apparent that I have provided a novel and simple spraying device whichcan be quickly adapted to the spraying of various containers and which enables a spray application to be made selectively, for example, to those interior surfaces definin the cavity in the. container, such as in a bread pan.

This is a continuation in part of my application Serial No. 38,498, filed July 13, l948,-and now abandoned.

I claim:

1. In a device of the character described, means for spraying a material under pressure at a spraying station to apply said material to a redetermined uniform area at said station, a conveyor movable past said station for transporting a series of objects each having an exposed area to be sprayed corresponding substantially to said predetermined uniform area, means for supplying a material to be sprayed to said spraying means, means for supplying air at a first pressure to said spraying means to spray said material in atomized form, air operated means controlling release of air to said spraying means, means for supplying air under a second pressure relatively great with respect to said first pressure to said air operating means, a first control means independently operated'by an object on said conveyor to release the high pressure air to said air operating means, and a second control means spaced a relatively short distance beyond said first control means in the direction of advance of said conveyor and independently operated by an object on said conveyor while in engagement with said first control means to cut off release of the high pressure air to said air operating means.

2. In a device of the character described, means for spraying a material under pressure at a spraying station to apply said material to a predetermined uniform area at said station, a conveyor movable past srid station for transporting a series of objects each having an exposed area to be sprayed corresponding substantially to said predetermined uniform area, means for supplying a material to be sprayed to said spraying means, means for supplying air at a first pressure of about 8 pounds per square inch gauge, to said spraying means to spray said material in atomized form, air operated means controlling release of air to said spraying means, means for supplying air under a pressure of about 85 pounds per square inch gauge to said air operating means, a first control means independently operated by an object on said conveyor to release the high pressure air to said air operating means, and asecond control means spaced a relatively short distance beyond said first control means in the direction of advance of said conveyor and independently operated by said object on said conveyor while said object is in engagement with said first control means to cut-oil release of the high pressure air to said air operating means.

3. In a device of the character described, means for supplying air under a first elevated pressure. means for spraying a material in atomized form at a spraying station, pressure reducing means for delivering air from said -air supply means to said spraying means at a second pressure less than said first pressure, control means operated by air under said first pressure for controlling a supply of air under said second pressure to said spray means, a conveyor movable over a path including said spraying station to transport a series of uniformly sized objects to be sprayed past said station; means for supplying air under said first pressure to said control means including a conduit between said air supply means and said control means and including ,a first valve and a second valve arranged serially in said conduit with an outlet of said first valve connected directly to an inlet of said second valve, means biasing the first valve to closed position, means biasing the second valve to open position, a first means for engaging an object on said conveyor during traverse thereof toward said spraying station to open the first valve, and a second means for engaging an object on said conveyor during traverse thereof along said path to close the second valve while said first valve is in engagement with said object, said second means being spaced a short distance from said first means in the direction of advance of the conveyor.

4. In a device of the character described, means for supplying air under a first elevated pressure, means for spraying a material in atomized form at a spraying station, pressure reducing means for delivering air from said air supply means to said spraying means at a second pressure less than said first pressure, control means for said air supply to said spraying means operated by air under said first pressure. a conveyor movable over a path including said spraying station to transport a series of uniformly sized objects to be sprayed past said station; and means for supplying air under said first pressure to said control mean including a conduit between said air supply means and said control means and including a first valve and a second valve arranged serially in said conduit with an outlet of said first valve connected directly to an inlet of said second valve, means biasing the first valve to closed position, means biasing the second valve to open position, ii. first control element in the path of an object on said conveyor for opening said first valve upon engagement with an object, and a second control element for closing said second valve and spaced from said first control element a relatively short distance in the direction of advance of the conveyor.

5. In a device of the character described. mean for supplying air under a first elevated pressure, means for spraying a material in atom ized form at a spraying station, pressure reducing means for deliverin air from said air supply means to said spraying means at a second pressure less than said first pressure, control means for said air supply to said spraying means operated by air under said first pressure, a conveyor movable over a path including said spraying station to transport a series of uniformly sized objects to be sprayed past said station; and means for supplying air to said control means including a conduit between said air supply means and said control means and including a first valve and a second valve arranged serially in said conduit, means biasing the first valve to closed position, mean biasin the second valve to open position, a first control element in the path of an object on said conveyor for opening said first valve upon engagement with an object and for maintaining said first valve open during such engagement, and a second control element adjacent to said first control element and in the path of an object on said conveyor engaged with said first element for closing said second valve and for maintaining said second valve closed during only a portion of the engagement of said first control element with said object.

6. In combination, means for spraying a material, a conveyor movable over a path to transport articles serially past said spraying means, means for supplying air to the spraying means for spray application of a material onto said articles, and means for controlling the supply of air to the spraying means and comprising an air supply for energizing said spraying means, a first first valve means biased toward closed posiiton and a second valve means biased toward open position, said valve being arranged serially with said first valve interposed in said air supply ahead of said second valve to have an outlet of said first valve connected directly to an inlet of said second valve, a first control element for opening the first valve means upon engagement of said first control element with an object on said conveyor, and a second control element for closing the second valve means upon engagement of said second control element with said object during at least a portion of the engagement of said first control element with said object, said second control means being spaced from said first control means a relatively short distance along the path of the conveyor.

7. In combination, means for spraying a madistance along the and means for rendering the spraying means effective to spray material onto an object moved past the spraying means by said conveyor and comprising a first control means effective to energizesaid spraying means upon and during engagement of said first control mean with said object during movement of said object past said spraying means, and a second control means efl'ective to de-energize said spraying means during energization thereof by said first control means upon and during engagement of said second control means with said object during movement of said object past said spraying station, said second control means being spaced from said first control means a relatively short path of the conveyor.

In a device of the character described, a conveyor movable over a path including a spraying station, spray meansat said station to apply spray material to a predetermined uniform area at said station, control means for said spray means including a first valve and a second valve connected in series with an outlet of said first valve connected directly to an inlet of saidsecond valve, said control means controlling flow of an actuating fiuid to said spray means through a conduit, the second valve being normally open and the first valve being normally closed, a first means for opening the first valve when said first means is engaged by an object moving past said station and having an exposed area to be sprayed corresponding substantially to said predetermined uniform area, and a second means for closing the second valve, said second means being spaced a relatively short distance from said first means in the direction of advance of said conveyor for engaging an object moved by the conveyor while said object is in engagement with said first means.

9. In a device of the character described, a conveyor movable over a path including a spraying station, spray means at said station to apply spray material to a predetermined uniform area at said station, control means for said spray means including a first valve and a second valve connected in series with an outlet of said first valve connected directly to an inlet of said second valve, said control means controlling fiow of an actuating fluid to said spray means through a conduit, the second valve being normally open and the first valve being normally closed, a first means engaged by an object moving past said station for opening the first valve, and a second means engaged by an object. during and following engagement thereof with said first means for closing the second valve, said second means being spaced from said first means a relatively short distance in the direction of advance of said conveyor.

ROBERT W. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

